Abstract: A power converter path of a modular multilevel power converter includes a multiplicity of modules forming an electrical series circuit. The series circuit includes four groups of modules, of which two successive or sequential groups are disposed one above the other in a tower structure. A modular multilevel power converter with a power converter path is also provided.

Abstract: A power converter path of a modular multilevel power converter includes a multiplicity of modules forming an electrical series circuit. The series circuit includes four groups of modules, of which two successive or sequential groups are disposed one above the other in a tower structure. A modular multilevel power converter with a power converter path is also provided.

Abstract: A method of monitoring queues in real time can include building a master list specifying available queues, wherein each queue within the master list is associated with a user, and registering each queue specified by the master list with an instant messaging system. The method further can include sending, to a client, a secondary list of queues associated with a particular user and selected from the master list. The secondary list can be formatted as an instant messaging contact list. A presence on the instant messaging system can be established for each queue specified by the secondary list. The method also can include obtaining queue information for queues specified by the master list and making the queue information, for queues specified by the secondary list, available to the client via the instant messaging system.